Drinking Water Wells
A new U.S. Geological Survey (USGS) report (PDF 7.62 MB) included information on about 2,100 domestic wells in 48 states, including wells in Nebraska. As many as 219 water quality properties and contaminants were measured in the study. Overall, more than 20 percent of private domestic wells sampled nationwide contained at least one contaminant at levels of potential health concern. While the quality of water from private wells in Nebraska is not regulated by federal or state mandates, information from the study can help private well owners as they make informed decisions about their drinking water supply.
Nitrate was the only contaminant derived primarily from man-made sources that was found at concentrations greater than the human-health benchmark in more than 1 percent of wells nationwide. Nitrate concentrations varied by land use and were higher in wells located near agricultural land than in other areas. Twenty-five percent of 436 wells in shallow groundwater beneath intense agricultural land use had concentrations of nitrate greater than the standard for public water supplies (10 parts per million.) These nitrate findings are consistent with many previous studies finding relatively high nitrate concentrations in some agricultural areas. Sources of nitrate in groundwater include fertilizers, animal waste, and human waste.
Contaminants most frequently found nationwide at concentrations greater than benchmarks included radon, arsenic, uranium, nitrate, and fluoride. Each was individually greater than its benchmark in about 1 to 7 percent of wells nationally. Radon, uranium, arsenic, and nitrate were frequently present in Nebraska wells sampled. Except for nitrate, these contaminants in groundwater originate primarily from natural geologic sources. Other contaminants detected nationwide at any concentration included herbicides, insecticides, solvents, fumigants, and gasoline chemicals.
Potential health concerns were identified by comparing measured concentrations to Maximum Contaminant Levels specified by the Safe Drinking Water Act for contaminants regulated in public water supplies and USGS Health-Based Screening Levels for unregulated contaminants.
Unlike public water supplies, the quality of private water sources in Nebraska is unregulated by federal or state mandate. Thus, well owners are encouraged to have their well water tested annually and make sure their well is properly maintained to help protect their health and safety.
"A Home Buyer's Guide to Private Wells in Nebraska" (a senior project by UNL Environmental Studies Seminar students Carla Ahlschuede, Lindsay Grim, Casey Priebe, and Andy Springer) offers basic information for people considering purchase of rural property with a private drinking water well. (13 minutes 47 seconds)